1. Field of the Invention
The invention relates to hand tools, and more particularly to hand cutting tools actuated by squeezing hand-grippable handles together to bring cutting surfaces in shearing action past one another.
2. Description of the Related Art
Hand cutting tools are used to cut wire, cable and sheet material. Cutting tools can simply consist of a pair of elongated handles that are pivotably mounted together at an intersection point near one end. A sharpened cutting surface of one handle is forced against a blunt anvil on the other handle, thereby cutting a workpiece that is placed between the two surfaces. Alternative cutting actions can be used, including shearing with scissoring action. These simple tools typically are made of forged high carbon steel, which experiences significant wear if harder materials, such as aluminum or copper, are cut.
More recently, compound linkages have been used on cutting tools to permit a greater force to be applied to the workpiece upon squeezing of the handles. With such compound linkages, the distance the cutting surfaces move is less than the distance the handles move. However, the leverage provided by the linkage applies a much greater force to the workpiece than the simple hinged tools.
With the significantly higher force of compound linkages and the corresponding ability to cut harder materials comes an increase in wear to the cutting surfaces. The use of materials for the cutting surfaces that do not wear as severely increases the cost of the tool significantly, because the entire tool, or at least a significant portion of it, must be made of the harder, more expensive material. Therefore, the need exists for a hand cutting tool that has a significantly increased useful life, but which is still economically feasible to manufacture.